December in the garden

There may not be a lot of rain this winter, so be ready to collect it when it happens.

There may not be a lot of rain this winter, so be ready to collect it when it happens. (Getty Images/iStockphoto)

Nan Sterman

With the promise of La Niña this winter, our gardens are not likely to get frequent help from Mother Nature. That said, climate scientists suggest that when we do get a rainstorm, it could be a doozy. So what is a gardener to do? Be prepared.

• Be prepared for dry conditions and be prepared for big rainstorms. Always start from the top.

• Hire a certified arborist to evaluate your trees. The concerns include dead or weak branches that could drop and poorly rooted trees that could topple in a big storm. Make this an annual task, and work only with a certified arborist who commits to being on site while work is being done on your trees.

• Clean out the rain gutters. When gutters are filled with leaves and debris, there’s no room for them to divert water from your roof, so the water just flows over the edges, onto plants below, often beating them up pretty badly.

• Install swales and redirect downspouts to the swales. Allow water to pool while it absorbs into the surrounding soil. Think of it as banking water for long-term withdrawal by your plants’ roots.

• Since rain barrels have a limited volume, think about using several in a daisy chain. Better yet, install a high-capacity cistern to hold rainwater either above or below ground.

• When you set up your water-capture systems, remember to include a diversion valve so the first flush can go down the drain. Pollutants and debris land on the roof all through the dry season. That first rainfall rinses most of it off, so let the first flush go, then collect what falls after that.

• While collecting water is important, do it only in the right places. Don’t let water accumulate in dishes under potted plants, in buckets waiting for other uses, or in other places where constant moisture can drown plant roots, or become a mosquito nursery.

• Check your irrigation controller to be sure it is on the reduced winter schedule. In the cooler, shorter days, plants need less water, especially if it rains.

• When Santa Ana winds are predicted, water deep and long the day before. At all other times, water only if it hasn’t rained for a while, AND if when you poke your finger into the soil, its dry to the second knuckle.

• Cooler, wetter weather is a great time to work in the garden, but wait a few days after a rainfall. Stay off wet soil to avoid compacting it.

• Plant natives, plants from other Mediterranean climates and desert climate plants, too. They’ll establish now to tolerate next summer’s heat and drought.

• Look to the hills. The native plants are in active growth cycle now. What’s green? That’s what to plant.

• Prune deciduous fruit trees now. First, find out which parts of the branch to cut. Different kinds of trees produce fruits on different parts of their branch. The branches of apple trees, for example, grow short side spurs where the fruits develop. Pluots fruit along the length of their branches. Figs make fruit at the tips of branches. Cut off the wrong part and you’ll have no fruit, so do your homework before you start to prune.

• Work clean. Disinfecting pruning shears, saws, loppers, etc. between plants stops the spread of diseases and pathogens from one tree to the next. I use spray bathroom disinfectant to clean all of my tools. When I am done for the day, my tools get sprayed again, dried, and then I lubricate the moving parts before I put the tools away.

• Prune and spray roses now. Let them grow large and bushy rather than pruning them down to nubs. Since roses flower at the ends of branches, the more healthy branches, the more flowers.

• Move cold-sensitive container plants like plumeria, tender bromeliads, tender succulents, etc. under the eaves to protect them. For cold-sensitive plants in the ground, cover them with floating row cover (now plastic). Use clothespins to secure the covers in place.

• Watch for frost across the county. We don’t get hard frosts but plants from coast to mountains can suffer frost damage on a cold night.

• If plants sustain frost damage, let the damaged leaves and branches remain in place to protect the rest of the plant. You can cut them off after the last chance of frost has passed in spring.

• Clean up the garden. Many plants accumulate dead, brown, branches underneath healthy green growth. This is a good time to figure out what is still healthy and living, and what is dead. Cut out the dead and cut back the living so the plant will resprout healthy and green next spring.